plate rolling machine design

I would like to build a sheet metal rolling machine, to be able to bend max. 1-1,2 m long, 2mm thick sheet metals.
I found that the pinch type rollers can eliminate the flat sections of the bended part, but I didn't really find a good source, where it is explained the design differences between the different types of rolls (pyramid type, pinch type, double pinch type). I decided to built a pinch type machine.

I want to build almost the same structure, only a few minor extra changes.
I began to design the machine, but I'm stuck on what the horizontal distance should be between the lower and the upper roll. I saw machines with no shift between the centers, they were at a vertical line, and I saw shifted centers.

I don't know it matters or not, that the two centers are shifted or not.

I don't know what the difference is either, but all the sets of rolls i have seen are "pyramid" type with 3 rolls; one or more of which can be adjusted ("centres shifted") to allow the bend to be started from a flat sheet and the required radius to be achieved.
Conical shape can be rolled by adjusting one end of the roll more than the other.

The design you linked to has lots of nice features, including a release to allow tightly rolled bands to be removed from the roll; sprocket drive to 2 of the 3 rolls.